A conventional electrophotographic image forming apparatus detachably accommodates developing cartridges therein. Such a developing cartridge includes a cartridge frame for accommodating toner, and a developing roller supported in the cartridge frame.
One developing cartridge that has been proposed includes a developing roller configured of a metal developing-roller shaft, and a rubber roller covering the developing-roller shaft while leaving left and right ends of the shaft exposed. A bearing member is fixed by screws to a right wall of a cartridge frame for receiving and rotatably holding the right end of the developing-roller shaft (see Japanese Patent Application Publication No. 2009-042327, for example).
In this developing cartridge, the right endface of the rubber roller confronts but is separated from the right wall of the cartridge frame in a direction along the developing-roller shaft (hereinafter referred to as the “axial direction”). The bearing member restricts the developing roller from moving outward in the axial direction (rightward) relative to the cartridge frame.